Mechanical devices used to lift heavy loads (commonly referred to as “jacks”) are well known and used for a variety of different applications, including vehicle maintenance and repairing or changing tires, among other things. These jacks may utilize screw threads, hydraulics, or other mechanisms to generate a lifting force. Most jacks utilized for vehicles, such as cars, have a maximum lifting capacity in the range of 1.5 to 3 tons, but that capacity may be more or less depending on the jack's intended application. A common jack employed by many vehicle manufacturers is the “scissor” jack, or a jack utilizing threading or “jackscrew” that causes lifting arms to pivot and raise or lower a lifting surface on the scissor jack depending on the rotation of the jackscrew. The scissor jack has been used for a decades and is desirous for many vehicle manufacturers because it is generally reliable, generally maintenance free, and relatively compact when placed in a collapsed (non-lifting) position.
One significant problem with vehicle jacks, particularly scissor jacks, is the lack of stability when placed in a raised (lifting) position. This lack of stability generates an unsafe environment for users of the jacks, leading to many injuries and even fatalities over the years. The lack of stability and increased chance for user injury is exacerbated when the vehicle jack is utilized in combination with an unstable or uneven ground surface upon which the jack rests. Over the years, there have been some advances to increase stability and reduce injuries. These advances, however, have their own associated disadvantages.
One well-known method and device utilized to increase stability includes the use of one or more “jack stands.” These jack stands are employed in connection with a vehicle jack and are often used as an independent means to support the weight of the vehicle after the vehicle has been raised. As implied, the jack stands do nothing to increase the stability of the jack during the lifting or lowering process. Moreover, because of the size and cost of most jack stands, most vehicle manufacturers do not incorporate or utilize jack stands on the vehicle. As such, users desirous of utilizing jack stands have to expend the time and money to purchase one. Additionally, even if the jack stands are utilized, they often do not facilitate the creation of a more stable support surface because of the shape of the legs of the jack stands.
Another known method and device utilized to increase the stability of a car jack during the lifting and lowering process includes the jack utilizing a telescoping base. One such example includes the “jack track” embodied in U.S. Pat. No. 1,887,924, issued Nov. 15, 1932. These telescoping bases are problematic in that they only extend in one directional axis, which would be insufficient to generate a stable surface for the jack positioned over an uneven surface in two or more directions. These telescoping bases also utilize numerous inter-working components that require additional manufacturing and installation time and costs, thereby increasing the overall retail price. The telescoping bases are also more prone to overall failure should one of the numerous telescoping components break or fail, which is more likely for these telescoping or extending bases considering the volatile joints, links, and components utilized therein. Many of these telescoping bases also increase the overall size of the jack, thereby leaving the desired compactness of the jack unfulfilled. Some known jacks also utilize foldable bases, but these too suffer from many of the above-mentioned disadvantages, including the use of multiple components prone to failure and increased costs and the increased size of the jack when in a collapsed state.
Therefore, a need exists to overcome the problems with the prior art as discussed above.